The manufacture of oscillating mechanisms for micromechanics, and in particular for clock/watch making, often resorts to elastic restoring means generally formed by springs. Being delicate to implement, these components are in addition difficult to position and require a qualified workforce or/and expensive apparatus. Such springs are generally made of steel in order to have a long lifespan and at the same time a large restoring moment. Manufacture thereof is very much dependent upon the quality of the initial material used but also upon the thermal treatments which are effected. For this reason, manufacture of springs is not very reproducible and all the mechanisms incorporating them must be subject to regulation or adjustment.
Elastic restoring means in the form of shape memory materials are also known, such as vulcanised rubber or certain elastomers. The use of elastic blocks of this type is known in heavy mechanical engineering, often in conjunction with a silent-block function or more generally for damping. Apart from the fact that their use in micromechanics is difficult, it is observed that precisely these properties of damping vibrations, and therefore of damping oscillations, run counter to the objective if, on the contrary, maintaining an oscillation is desired, with the minimum of damping.
Some devices have been developed with elastic wheels, for instance a mobile element of the train of watchworks, according to document CH 343 897 in the name of Rolex, comprises an elastic linking device which becomes taut under the influence of the motor spring when the escapement wheel is stationary or during its slight backward movement before disengagement, and slackens at the moment of disengagement so as to act on the set of pallets with a constant force in order to reduce the separation between the teeth of the escapement wheel and the impulse plane of the pallet stones of the set of pallets at the beginning of each impulse movement.
Elastic wheels are known from documents CH 6659 in the name of Lambert, with S-shaped arms, or also DE 271 4020 in the name of Beiter, with spiral arms, or also EP 1 580 624 in the name of Pierre Kunz, which has a mobile element which is sufficiently elastic to undergo displacements without changing its centre difference of axes and without changing its meshing ratio, or EP 1 457 844 in the name of Pierre Kunz which uses a spacer made of elastic foam in place of the elastic arms of the preceding case. Anti-noise pinions with an elastic structure are also known from document FR 2 641 351 in the name of Alcatel, and also wheels comprising integrated dampers as in document EP 1 253 275 in the name of Siemens.